A new study on adolescents with prenatal cocaine exposure has found alternations in the functional connectivity of the amygdala — a brain region that plays an important role in regulating arousal and emotions.

The findings, which appear in Drug and Alcohol Dependence, could help explain why adolescents who were exposed to cocaine in the womb tend to have less control over their emotions and are more likely to become distracted.

“Prenatal cocaine exposure (PCE) is a public health concern because psychoactive drugs may impact the developing brain and lead to developmental and learning problems, as well as a range of behavioral and social consequences. Improved understanding of its long-term effect relies on longitudinal characterization of the associated alterations in the brain,” said study author Zhihao Li, a professor at Shenzhen University.

In the study, the researchers used resting-state functional magnetic resonance imaging to compare the brain structure of 25 adolescents with prenatal cocaine exposure and 16 non-exposed adolescent controls. The participants underwent the brain scans twice, about 2 years apart.

The researchers found that functional connectivity within the brain’s emotion network tended to increase in the PCE group, while the opposite was true for the control group.

In a similar study, published in 2016, Li and his colleagues observed heightened amygdala activation in adolescents with prenatal cocaine exposure during a working memory task that included emotional distractions.

“PCE is associated with a long-term effect of arousal dysregulations in adolescents. This dysregulation is specifically shown here by altered functional connections of the amygdala — a brain region important for emotional arousal,” Li told PsyPost.

The researchers accounted for factors such as prenatal exposure to other drugs and household income.

“Although confounding factors of polydrug exposure are statistically control in this study, contributions from other substance exposure (e.g. alcohol, tobacco, marijuana) are still possible. In other words, the reported effect may not be specific to cocaine,” Li said.